Rear sprocket mounting question

  • katit
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Rear sprocket mounting question

28 Jul 2022 19:34
#871226
I forgot how it was, but when I put sprocket on - there is visible gap where it mounts to wheel. I have 2 sprockets and it's the same. Do I miss something or it should be like that?

 
78 KZ650B2A - resto in progress
www.kzrider.com/forum/11-projects/615161...s-1978-kz650-project
Other bikes: 1978 BMW R100/7, 1978 Moto Guzzi T3, 2016 DRZ400s

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  • Ian_B
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Re: Rear sprocket mounting question

28 Jul 2022 22:36
#871229
Something definitely wrong there! The sprocket should be a fairly close (even tight) fit on the hub. This ensures that the sprocket runs concentric. It looks like the bolt holes line up, so it may be that the old sprocket was held and located by the bolts only - really bad engineering practice.

Choices would be to either find a sprocket with a hole that exactly matches the hub, or find / have made a metal adaptor ring to fill the gap.

Ian

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  • Wookie58
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Re: Rear sprocket mounting question

28 Jul 2022 22:50
#871230
Is there a square shoulder at these points that stop any sideways movement ? If yes you are Ok if no that is bad as there will be a lot of stress on the bolts and also the sprocket won't run true. There is a risk of the bolts breaking

 

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  • Scirocco
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Re: Rear sprocket mounting question

29 Jul 2022 02:20
#871239
JTSprockets shows three rear sprokets and two hub diameter

www.jtsprockets.com/catalogue/?searchtyp...kz650#search-results

 
 
 
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  • katit
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Re: Rear sprocket mounting question

29 Jul 2022 06:59 - 29 Jul 2022 07:11
#871247
JTSprockets shows three rear sprokets and two hub diameter

www.jtsprockets.com/catalogue/?searchtyp...kz650#search-results

 
 
 


Thank you! That makes sense. Sprocket is 80. Second sprocket is 80 as well (from spare bike). But hub is 74. So, I need different sprocket. It matches your diagrams.
However, I swear! It was tight on a hub when I took it apart, or maybe I forgot.. I only had hub "away" when it was vapor blasted, but I doubt the guy had another one in posession and mixed them.

I will go with a version that I had wrong one to begin with.

EDIT. Mystery solved, correct one ordered. Does anybody need 2 nice sprockets? :)

 
78 KZ650B2A - resto in progress
www.kzrider.com/forum/11-projects/615161...s-1978-kz650-project
Other bikes: 1978 BMW R100/7, 1978 Moto Guzzi T3, 2016 DRZ400s
Last edit: 29 Jul 2022 07:11 by katit.

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